1. Field of the Invention
The present invention relates to a communications system, and more specifically to a radio communications system of the so-called blind channel system in which display of the radio channel other than a calling channel is eliminated.
2. Description of Background Information
In radio communications systems such as amateur radios of the VHF band or the UHF band, or CB (Citizens Band) of the United States, it is general to use a single call channel and a plurality of speech channels. Also, in Japan, a new radio communications system of this type has been put to practical use to meet the increasing requirement of the personal radio communications system. The blind channel system is one of the radio communications systems of this type, in which the display of channel is eliminated. Further, the blind channel system is equipped with an automatic channel assignment function for automatically shifting the frequency of a station of the other side of communication (referred to as a responding station hereinafter) to a selected speech channel.
In the case of the blind channel system, however, there was a drawback such that it is not possible to return to the selected speech channel on which activity was taking place once a reset switch provided to the system is operated to reset the frequency of the system at the call channel.
In addition, if the reset switch is not operated after the completion of a call, the system will be continuously operating on the selected speech channel and it becomes impossible to communicate with the other stations unless the power switch is turned off.